The button element defines a single button stimulus and specifies how the button is presented.
<button buttonname>
/ caption = "text"
/ dropposition = (x value, y value) or (x constant, y constant)
/ dropsource = value or boolean
/ droptarget = property or boolean
/ erase = true(red value, green value, blue value) or true(color value) or true(color name) or false
/ fontstyle = ("face name", height, bold, italic, underline, strikeout, quality, character set)
/ halign = alignment
/ height = numeric expression
/ hposition = x expression
/ monitor = integer
/ onanimate = [expression; expression; expression; ...]
/ onprepare = [expression; expression; expression; ...]
/ position = (x value, y value)
/ size = (width variable, height variable)
/ valign = alignment
/ vposition = y expression
/ width = numeric expression
</button>
button.buttonname.bottom
button.buttonname.caption
button.buttonname.dropsource
button.buttonname.droptarget
button.buttonname.dropx
button.buttonname.dropy
button.buttonname.erase
button.buttonname.erasecolor
button.buttonname.erasecolorblue
button.buttonname.erasecolorgreen
button.buttonname.erasecolorred
button.buttonname.height
button.buttonname.heightpct
button.buttonname.heightpx
button.buttonname.hposition
button.buttonname.left
button.buttonname.monitor
button.buttonname.name
button.buttonname.resetinterval
button.buttonname.right
button.buttonname.skip
button.buttonname.stimulusonset
button.buttonname.timestamp
button.buttonname.top
button.buttonname.typename
button.buttonname.vposition
button.buttonname.width
button.buttonname.widthpct
button.buttonname.widthpx
button.buttonname.xpct
button.buttonname.xpx
button.buttonname.ypct
button.buttonname.ypx
None.
button stimuli provide a convenient means of overwriting previously presented stimuli during a presentation sequence, or for drawing background to be presented behind other stimuli.
The following defines a blue circle that appears on the right side of the screen:
<button bluecircle>
/ shape = circle
/ color = (0, 0, 200)
/ position = (80%, 50%)
</button>